[netcdf-java] NPE when reading Grid Variable

• To: "netcdf-java@xxxxxxxxxxxxxxxx" <netcdf-java@xxxxxxxxxxxxxxxx>
• Subject: [netcdf-java] NPE when reading Grid Variable
• From: Aaron Braeckel <braeckel@xxxxxxxx>
• Date: Tue, 17 Mar 2015 17:24:57 -0600

Hello,

with 4.5.5 and 4.6.0-SNAPSHOT when I read a GRIB file and call
Variable.read() I get a NullPointerException.  I've placed a copy of my
file at http://www.ral.ucar.edu/~braeckel/pgbh02.gdas.CLWMR.975mbar.grb2.
Here is my code:

GridDataset dataset = null;

try {
  dataset = GridDataset.open( "pgbh02.gdas.CLWMR.975mbar.grb2");
  System.out.println( "Opened "+dataset);
  for( GridDatatype grid : dataset.getGrids() ){
    Variable v = grid.getVariable();
    Array a = v.read();
    System.out.println("Read data for "+grid.getName());
  }
} catch( IOException e ) {
  e.printStackTrace();
}

if( dataset!=null)
  dataset.close();

This results in the following NPE (this is 4.6.0-SNAPSHOT):

Exception in thread "main" java.lang.NullPointerException
    at
ucar.nc2.grib.grib2.Grib2DataReader2.getData40(Grib2DataReader2.java:756)
    at
ucar.nc2.grib.grib2.Grib2DataReader2.getData(Grib2DataReader2.java:117)
    at ucar.nc2.grib.grib2.Grib2Record.readData(Grib2Record.java:327)
    at ucar.nc2.grib.collection.Grib2Iosp.readData(Grib2Iosp.java:470)
    at ucar.nc2.grib.collection.GribIosp$DataReader.read(GribIosp.java:1013)
    at
ucar.nc2.grib.collection.GribIosp.readDataFromCollection(GribIosp.java:935)
    at ucar.nc2.grib.collection.GribIosp.readData(GribIosp.java:880)
    at ucar.nc2.NetcdfFile.readData(NetcdfFile.java:1980)
    at ucar.nc2.Variable.reallyRead(Variable.java:868)
    at ucar.nc2.Variable._read(Variable.java:839)
    at ucar.nc2.Variable.read(Variable.java:717)
    at ucar.nc2.dataset.VariableDS.reallyRead(VariableDS.java:523)
    at ucar.nc2.dataset.VariableDS._read(VariableDS.java:507)
    at ucar.nc2.Variable.read(Variable.java:717)

Have you seen this before?
Aaron

• Follow-Ups:
  • Re: [netcdf-java] NPE when reading Grid Variable
    • From: John Caron